1. Field of the Invention
This invention relates to a light emitting diode lamp with high heat-dissipation capacity, particularly to a lamp without the additional need of a circuit board, and the lamp itself has heat sink unit so as to obtain performance with good heat dissipation efficiency.
2. Brief Description of the Prior Art
Accompanying with perpetual increase of the power of light emitting diode (LED), the percentage of using LED as lamp for illumination is gradually boosted. However, the working waste heat of LED is relatively increased with respect to the raising of power. The temperature increase of the high power LED, reduction on working efficiency and even the damage of LED will be happened if the exhausted waste heat amount is unable to be raised. When reviewing the present method of heat dissipation for LED lamp, for example the working waste heat of LED contacts with the heat sink through the circuit board and heat sink paste, there are three major defects of heat resistance in the present method of heat dissipation for LED lamp listed as follow.    1. A layer of polymer with high heat-resistance for insulation package exists between the heat sink and the LED components such that the heat generated by the LED is unable to be transferred to the heat sink promptly due to the low thermal conduction efficiency of the polymer layer. Thus, the temperature increase of the LED, reduction on working efficiency and even the damage of LED will be caused to happen.    2. LED is mounted on the polymer circuit board with high heat-resistance insulation. As stated above, the heat generated by the LED is unable to be transferred to the heat sink promptly due to the low conduction efficiency of the polymer layer with high heat-resistance. Thus, the temperature increase of the LED, reduction on working efficiency and even the damage of LED will be caused to happen.    3. Heat sink paste is used between the layers of the structure. Since the thermal conductivity of the heat sink paste is only 1˜5 w/k·m, the heat generated by the LED is unable to be transferred to the heat sink promptly. Furthermore, bubbles is likely to be produced between the layers of structure and the heat sink paste due to anthropogenic factor during distribution of the heat sink paste, or various heat-resistance situations occur in view of structural defect. Therefore, huge heat unsteadiness will be occurred on the components.
So far, the way of solving the above heat-resistance problem is mostly to increase the area of heat sink or to raise the rotation speed of fan so as to enhance the heat dissipation efficiency. However, this measure of increasing the efficiency in the heat sink terminal fails to contribute efficiently and reasonably to the improvement or solution with respect to the heat transfer efficiency between the heat source (i.e., the LED) and the heat dissipating terminal (i.e., the heat sink).
So far, there are several ways developed to solve the above heat dissipation problem listed as below.
Firstly, in Japanese Patent No. JP2004-200347, an electrically conductive mixture using diamond and metal material is disclosed as an electrically conductive heat-dissipating layer of lamination between the p-n diodes of the LED. However, this technology only improves the heat dissipation structure in the interior of the LED, thus does not provide any efficient solution with respect to the heat jamming in the insulation package layer with high heat-resistance outside the LED.
Secondly, in Japanese Patent No. JP-Heisei 5-347369, a constitution of small granular diamond mixing with epoxy resin or silicone resin is disclosed which is used as a heat-dissipating insulation package layer for electronic components. This technology improves heat dissipation problem of package layer on the upper portion of electronic components, but fails to solve defect problem of interface between the insulated circuit board with high heat-resistance and the heat sink paste. In addition, since this technology uses the constitution of small granular diamond mixing with epoxy resin, quartz granule or alumina granule as heat-dissipating insulation package layer for electronic components, the tensile stress feature of which is unable to meet the requirement of suppressing the damage caused by expansion and contraction caused by long-term temperature variation.
Thirdly, in PRC Patent No. CN15455148, a technology is disclosed in which LED with big power is adhered to the heat dissipating structure on the diamond substrate. This technology utilizes multi-layers heat sink paste between structure layers so as to achieve good heat transfer. However, in the case of practical application, heat resistance is raised in view of the increase of bubbles, impurities and material defect caused by the increase of interface. Therefore, this technology did not propose a total solution for heat transfer including the items of lowering heat-resistance channels, reducing the complexity of heat conduction structure and the number of interface, ensuring the interface bubbles of the heat sink paste.